Surfing is a popular sport all over the world. People taking it up in earnest are increasing, not only as a marine leisure activity but also as an athletic sport in late years. However, it is necessary to visit the sea shores that have the natural environment suitable for surfing in order to enjoy surfing.
A sea shore having the natural environment suitable for surfing is a contour of a coast to face to the open ocean that the big waves easily reach and become so-called big isolated waves to travel toward the sea shore. It needs to have a shallow seafloor topography that makes the waves easy to appear a wave breaking area followed by a wave about to break area in a line in the isolated waves.
The above-mentioned isolated wave does not mean the oscillating wave repeating the up and down movement at the same point, but it means the waves with some interval between each wave and every single wave traveling forward independently.
A wave especially suitable for surfing is a wave appearing to have a tubular curly portion in its vertical cross sectional view by emerging a wave breaking area followed by a wave about to break area in a line in the isolated waves. This makes it possible for surfers to play surfing by sliding toward from the wave breaking area to the wave about to break area of these tubular curling wave portions.
The coasts where the waves are formed suitable for surfing are limited to the places where the natural conditions are satisfied. It is impossible to enjoy surfing all over the world.
Therefore, the development of the wave making apparatus for surfing to enable enjoying surfing by making artificial waves suitable for surfing at pools in the prior art has been desired.
The following types are known as the wave making apparatuses to make artificial waves in a pool in the prior art.
A so-called flap type wave making apparatus is known.
As shown in FIG. 24, this type generates waves by reciprocating swinging of a part-submerged wave-making flap board whose bottom end is supported rotatably with a hinge in the bottom of the pool as a pivot.
A so-called piston type wave making apparatus is known.
As shown in FIG. 25, this type generates waves by a reciprocating motion pushing and pulling of a part-submerged piston installed to the axis.
An air compression type wave making apparatus is known.
As shown in FIG. 26, the air compressed type wave making apparatus generates waves by fluctuating water level by pulling up and pushing down water by air vacuum and air blowing by the vacuum pump or air blower in the air storage tank facing under the water line of the pool.
Also, a tank chamber type wave making apparatus is known.
As shown in FIG. 27, the tank chamber type wave making apparatus generates waves by falling the stored water in the pool by opening the gate momentarily after when water is stored until a fixed height in the water storage tank with pumps. The gate is installed to the lower portion of the water storage tank and facing to the waterline in the pool.
Furthermore, a water jet nozzle type wave making apparatus is known.
As shown in FIG. 28, this water jet nozzle type wave making apparatus generates waves by jetting pressurized water via the nozzle.
Prior art 1: JP Tokkai-Hei11-29904
Prior art 2: JP 2001-70497